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Large-Capacity Photonics-Assisted Millimeter-Wave Wireless Communication Enabled by Dual-Polarized SISO Link and Advanced MIMO Equalizer

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2024年第11期42卷 4048-4059页

作者： Cai, Yuancheng Luo, Wei Zhu, Min Liu, Xiang Zhang, Jiao Lei, Mingzheng Hua, Bingchang Li, Jiankang Xiang, Shitong Zhang, Junhao Zou, Yucong Ding, Junjie Chen, Xingyu Xiao, Jinbiao Yu, Jianjun Purple Mt Labs Nanjing 211111 Peoples R China Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China Mt Labs Nanjing 211111 Peoples R China Fudan Univ Key Lab Informat Sci Electromagnet Waves Shanghai 200433 Peoples R China

As the mobile communication evolves from sub-6 GHz to millimeter wave (MMW) frequency bands, the demand for high-speed wireless transmission rates exceeding hundreds of gigabits per second is becoming more and more prominent. It is one of the important cornerstones supporting numerous emerging bandwidth-consuming applications represented by the metaverse, digital twin and so on. So far, there is a huge room for improvement in wireless transmission rate, which is far inferior to the transmission capacity of fiber optic links. In this paper, we have proposed and experimentally demonstrated a large-capacity photonics-assisted MMW wireless communication system over 20-km fiber and 1.3-m wireless transmission at the W band. A dual-polarized single-input single-output (SISO) wireless link, instead of the commonly used 2 x 2 multiple-input multiple-output (MIMO) links, is used for the transparent transmission of optical polarization division multiplexing signal, which significantly simplifies the system complexity and enhances its robustness. In addition, the transmission performance is further improved by employing an advanced MIMO Volterra nonlinear equalizer. With the bit error ratio threshold of 2 x 10(-2), a record single-lane single-carrier wireless air interface rate (WAIR/ch/lambda) up to 504 Gb/s has been achieved for the first time. This solution we proposed provides opportunity for progress in the wireless air interface capacity close to the fiber-optic transmission capacity in the fiber-wireless integration transmission systems.

关键词： Large-capacity millimeter-wave communication multiple-input multiple-output nonlinear equalizer polarization division multiplexing single-input single-output W-band

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Scalp-Implanted Ultra-Wideband Circularly Polarized MIMO Antenna for Biotelemetry Systems

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SENSORS 2024年第23期24卷 7522页

作者： Song, Zhiwei Shi, Youwei Zheng, Xianren Wang, Yuchao Xinjiang Univ Sch Elect Engn Shengli Rd 666 Urumqi 830046 Peoples R China

This paper presents an innovative, compact, dual-element, implantable, ultra-wideband, circularly polarized multiple-input multiple-output (MIMO) antenna designed to operate within the 2.45 GHz industrial, scientific, and medical band, and both of its radiating units are circularly polarized antennas with polarization diversity. Specifically, antenna-1 exhibits left-handed circular polarization properties, while antenna-2 demonstrates right-handed circular polarization properties. The slots in the radiating patch and ground plane help the antenna achieve 690 MHz (2.14-2.83 GHz) ultra-wide bandwidth characteristics and circularly polarized characteristics. Additionally, a slit connecting two U-slots on the ground plane allows the antenna to achieve a wide effective circularly polarized axial ratio bandwidth of 400 MHz (2.23-2.63 GHz). The antenna is compact, with dimensions of 0.065 x 0.057 x 0.0042 lambda 03 (lambda 0 represents the free-space wavelength corresponding to the lowest operating frequency). The proposed antenna system's performance was evaluated with a seven-layer homogeneous human head model, a real human head model, and minced pork. This evaluation revealed that the antenna attained a peak gain of -24.1 dBi and an isolation level of 27.5 dB. Furthermore, the assessment included the antenna's link margin (LM), key MIMO channel characteristics, and Specific Absorption Rate (SAR) metrics. The results indicate that the antenna performs exceptionally well.

关键词： biotelemetry circular polarization multiple-input multiple-output polarization diversity ultra wideband

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Atmospheric turbulence degradation image restoration based on multi-input multi-output U-Net network

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LASER PHYSICS 2025年第2期35卷 025201-025201页

作者： Tao, Rong Zhang, Leihong Fang, Yao Yang, Haima Zhang, Dawei Xu, Banglian Sun, Quan Univ Shanghai Sci & Technol Sch Opt Elect & Comp Engn Shanghai 200093 Peoples R China Natl Univ Def Technol Coll Adv Interdisciplinary Studies Changsha 410073 Peoples R China

Aiming at the problem of limited ability to recover degraded images of atmospheric turbulence when they are severely damaged, a recovery method based on a multi-input multi-output U-Net network is proposed. The network can input information from multiple images at the same time, which improves the extraction and representation of image features. And it introduces multiple inverse convolutional head transposition attention during jump connection to better aggregate local and non-local pixel interactions and improve the recovery quality. Experiments demonstrate that the peak signal-to-noise ratio (PSNR) of the proposed network is improved by 4-5 db and the structural similarity is improved by about 6.4% compared with general recovery methods. Compared with the existing deep learning restoration methods, the PSNR of the improved network is improved by about 2-3 db, and the frequency structure similarity is improved by about 2.7%.

关键词： atmospheric turbulence image restoration multiple-input multiple-output attention mechanism

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Block Iterative Support Detection for Uplink Grant-Free MIMO-NOMA

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IEEE WIRELESS COMMUNICATIONS LETTERS 2025年第4期14卷 1264-1268页

作者： Lei, Ruibin Zhang, Xiaoxu Shi, Fengwen Zhou, Xiangwei Zhou, Zhengchun Liu, Jiaqi Southwest Jiaotong Univ Prov Key Lab Informat Coding & Transmiss Chengdu 611756 Peoples R China Louisiana State Univ Div Elect & Comp Engn Baton Rouge LA 70803 USA Avionics Co Ltd China Elect Technol Grp Corp Commun Nav & Surveillance Dept Chengdu 611731 Peoples R China

Grant-Free-Non-orthogonal multiple access (GF-NOMA) is a powerful means to reduce signaling overhead, provide a large number of connections, and support low latency requirements in 6G Internet of Things applications. However, the accuracy of multi-user detection (MUD) remains a challenge. In this letter, we propose a Block Iterative Support Detection (BISD) MUD algorithm for GF-NOMA, which exploits the spatial diversity gain and block sparsity provided by multiple-input multiple-output (MIMO) to improve the MUD accuracy of the traditional Iterative Support Detection (ISD) algorithm. The proposed BISD algorithm efficiently updates the active support set by block-wise non-zero judgment in each iteration to improve detection accuracy. Simulation results show that BISD improves the detection performance with faster convergence speed, compared with ISD and other traditional MUD algorithms for GF-NOMA.

关键词： Multiuser detection Vectors Accuracy MIMO Indexes Transmitting antennas Simulation Receiving antennas NOMA Internet of Things multiple-input multiple-output non-orthogonal multiple access multi-user detection compressive sensing

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A 1T2R High-Sensitivity and Dual-Channel Transceiver for Backscatter Communication Systems

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IEEE ACCESS 2024年 12卷 141841-141850页

作者： Lai, Sijia Zhao, Yuxiao Liu, Meng Xu, Shengliang Tang, Kuangfeng Min, Hao Fudan Univ Sch Microelect State Key Lab ASIC & Syst Shanghai 200120 Peoples R China

Owing to the rapid development of the ambient Internet of Things (IoT) industry, Backscatter Communication Systems (BCS) require higher receiver sensitivity for large-scale IoT scenarios than traditional Radio Frequency Identification (RFID) systems. This paper proposes a method of using multiple-input multiple-output (MIMO) technology to compensate for reflected signals in the 920 MHz backscatter communication systems. The researcher first created a MATLAB model to verify the theoretical feasibility and then built a One-Transmitter Two-Receiver (1T2R) BCS transceiver system compatible with the EPC global protocol for practical verification on LabVIEW. The ITIR and 1T2R tests were conducted using the National Instrument (NI) USRP-2952R device, the directional antennas, and the standard RF electronic tags. Through the process of superimposing and utilizing the phase shift between the two reflected carriers, it has been confirmed that the overall signal strength can be enhanced from 2.2 mV to 4.13 mV and 4.37 mV (nearly reaching 4.70 mV by using two Rx antennas in ideal conditions). After calculation, this advancement increases signal strength from -40.14 dBm (when using a single Rx antenna) to -34.18 dBm (when using two Rx antennas). The improvement in signal strength can provide a gain of 5.96 dB to the backscatter communication systems. Experimental results demonstrate that utilizing MIMO technology to the backscatter communication systems can effectively enhance the sensitivity of the receiver at 920 MHz.

关键词： Backscatter Transceivers Communication systems Radiofrequency identification Internet of Things Receiving antennas Sensitivity MIMO ambient Internet of Things backscatter communication systems radio frequency identification multiple-input multiple-output

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Two-Dimensional Ultrasonic Air Temperature Tomography Based on Phase Shift Processing of Multifrequency Measurements

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2024年 73卷

作者： Sukhanov, Dmitry Khalil, Amoon Tomsk State Univ Fac Radiophys Tomsk 634050 Russia Higher Inst Appl Sci & Technol Damascus 31983 Syria

An iterative method of transmission tomography of air temperature heterogeneities based on ultrasonic sensing is proposed. The direct dependence of the speed of sound in air on temperature is considered. Air flow and related nonstationary effects are not considered. A change in the speed of sound affects the change in the phase shift of ultrasonic waves passing through the area under study. The reconstruction of the spatial distribution of heterogeneities is carried out by tomographic processing of phase differences of waves passing in forward and reverse directions. The phase differences between forward and reverse propagation waves in an a priori specified medium are considered. In the first iteration, a homogeneous environment is considered as an a priori given environment, and in the second iteration, the reconstructed heterogeneous environment obtained in the first iteration is considered. The results of numerical modeling and the results of experimental studies at frequencies from 38 to 43 kHz are presented. The possibility of reconstructing the distribution of temperature of air is shown.

关键词： Tomography Image reconstruction Receivers Acoustics Temperature measurement Temperature distribution Media Air temperature heterogeneities inverse problems multiple-input multiple-output transmission tomography ultrasonic imaging

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Concrete Feedback Layers: Variable-Length, Bit-Level CSI Feedback Optimization for FDD Wireless Communication Systems

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2024年第10期23卷 15353-15366页

作者： Ji, Dong Jin Chung, Byung Chang Seoul Natl Univ Sci & Technol Dept Semicond Engn Seoul 01811 South Korea Gyeongsang Natl Univ Dept Intelligence & Commun Engn Tongyeong 53064 South Korea

In this work, we present the innovative Concrete Feedback Layers, designed to enable genuine bit-level, end-to-end Channel State Information (CSI) feedback using deep learning techniques. Overcoming the limitations of traditional discrete operations that impede gradient flow, these layers leverage the concrete distribution to facilitate efficient learning processes. Our extensive simulations reveal that these layers significantly enhance digital CSI feedback, achieving superior performance in terms of Normalized Mean Squared Error (NMSE) and cosine similarity compared to conventional feedback models. Furthermore, the integration of the Concrete Feedback Layers with the Feedback Bit Masking Unit (FBMU) allows for authentic bit-level variable-length CSI feedback, while maintaining a single adaptable model for various feedback lengths. This advancement marks a major leap forward in deep learning-based CSI feedback methods, potentially revolutionizing 6G communication systems with its flexibility and efficiency.

关键词： Machine learning for communications deep learning channel feedback multiple-input multiple-output variable-length feedback 6G wireless systems channel state information (CSI) end-to-end learning neural network architectures channel feedback multiple-input multiple-output variable-length feedback 6G wireless systems channel state information (CSI) end-to-end learning neural network architectures

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Design of compact UWB antenna using characteristic mode analysis and its quad-port MIMO realization with novel isolation technique

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JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS 2024年第4期38卷 443-459页

作者： Ghosh, Prabir Gorai, Abhik Behera, Subhrakanta Ghatak, Rowdra Kalinga Inst Ind Technol Sch Elect Engn Bhubaneswar 751024 India Natl Inst Technol Durgapur Dept Elect & Commun Engn Durgapur India

This paper presents a miniaturized Quad-Port MIMO antenna for UWB application. Employing Characteristic Mode Analysis, the single element UWB antenna is analysed to achieve a compact design. Using the Theory of Characteristic Mode, the significant modes and their current distribution are analysed, which helps to modify the radiator and ground plane to generate more significant modes to yield a wider frequency band. Four circular-shaped radiators with tapered feeds are placed orthogonally on the FR4 substrate to improve isolation, and partial ground planes are located on the opposite surface. Furthermore, a modified Pattee-cross-shaped parasitic element is introduced between the antenna elements and shorted with the ground planes via metallic shorting pins. This novel technique improves isolation compared to the conventional integration method of the partial ground planes through strip lines. The proposed antenna achieves less than -20 dB mutual coupling over most of the frequency band ranging from 2.51-18 GHz.

关键词： Characteristic mode analysis decoupling technique multiple-input multiple-output mutual coupling shorted parasitic element UWB antennas

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Semidefinite Relaxation for Moving Target Localization in Asynchronous MIMO Systems

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IEEE TRANSACTIONS ON COMMUNICATIONS 2024年第2期72卷 1075-1089页

作者： Wu, Xiaoping Mao, Xiaoting Qi, Hengnian Huzhou Univ Sch Informat & Engn Huzhou 313000 Peoples R China

Considering an asynchronous multiple input multiple output (MIMO) system, we propose to obtain the position and velocity of a moving target by applying differential time delay (DTD) and differential frequency shift (DFS) measurements. The asynchronous MIMO systems are generally divided into quasi-synchronous (QS) and fully-asynchronous (FA) systems. Applying the semidefinite relaxation (SDR), we further design two semidefinite programming (SDP) solutions: QS-SDP for quasi-synchronous systems and FA-SDP for fully-asynchronous systems. We give the conditions under which the QS-SDP and FA-SDP forms are shown to be sufficiently tight so that their solutions perform to the Cramer-Rao Lower Bound (CRLB) precision. The results from the simulations demonstrate that the QS-SDP and FA-SDP solutions require few transmitters and receivers to uniquely determine the unknown parameters of the moving target. Besides, the QS-SDP and FA-SDP solutions provide the equivalent performance to the CRLB even at high noise levels.

关键词： Moving target localization semidefinite programming multiple-input multiple-output asynchronous system

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Enhanced channel estimation with atomic norm minimization and reconfigurable intelligent surfaces in mmWave MIMO systems

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2025年第2期38卷

作者： Ganapathy, Sundar Muthusamy, Karthikeyan Arifa Inst Technol Dept Elect & Commun Engn Nagapattinam 611103 Tamil Nadu India Univ Coll Engn Pattukottai Dept Elect & Elect Engn Thanjavur Tamil Nadu India

The performance of millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems has been significantly enhanced by the incorporation of dynamic reconfigurable intelligent surfaces (RIS). This paper proposes a novel dynamic channel estimation technique that combines dynamic atomic norm minimization with dynamic RIS to optimize RIS-aided mmWave MIMO systems. Leveraging the dynamic nature of both atomic norm minimization and RIS, the proposed approach efficiently adapts to changing environmental conditions, providing robust and accurate channel estimation. By dynamically optimizing the RIS configuration, the system achieves improved spectral and energy efficiency, enabling high-speed and reliable communication in challenging mmWave environments. Theoretical analysis and simulation results demonstrate the effectiveness of the proposed dynamic channel estimation technique, highlighting its potential for enhancing the performance of future wireless communication systems. It presents a breakthrough dynamic channel estimation method for millimeter-wave (mmWave) multiple-input multiple-output systems that combines dynamic atomic norm minimization with reconfigurable intelligent surfaces (RIS). By adapting to environmental changes, this method significantly improves the accuracy of channel estimation. Dynamic RIS optimization increases spectral and energy efficiency and ensures fast and reliable communication in challenging mmWave environments. The simulations confirm the effectiveness of this system and show that it has the potential to revolutionize the future performance of wireless communications. image

关键词： BER channel estimation mmWave multiple-input multiple-output reconfigurable intelligent surfaces

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